Monitoring a Common Poorwill Nest Site

Male Common Poorwill Wasatch Mountains Utah County, Utah

An endeavor to locate and and photograph Great Basin Collared Lizards on June 8th resulted in a series of visits to a Common Poorwill nest site.

It all started as I was exploring prime habitat for collared lizards--a rocky desert hillside with sparse vegetation. That particular hillside was punctuated with scattered sagebrush and junipers. I was coursing along a south-facing rocky outcrop when a Common Poorwill, an elusive nocturnal bird, flushed from its daytime roost. I wondered if I had stumbled upon a nest site, but when I checked the base of the bush from which the bird flushed I noticed only a single feather. Perhaps it was just the bird's roost for the day, but I captured an image with my phone to preserve a GPS location in case I wanted to return a week or so later to check for evidence of nesting.

My search for collared lizards was quite productive and resulted in some nice photos. My friend Eric enjoyed the photos and asked if I'd take him out to the same location since he'd never photographed collared lizards. We made that trip the next day, June 9th.

I mentioned my encounter with the Poorwills as we hiked up the hillside and suggested we check the previous roosting site. As we approached that site two birds flushed, not from the previous bush, but from a nook of the rocky outcrop. Both birds flew quite a distance, without any attempt to do a distraction display so I could tell that they had no eggs nor chicks to protect. There was no evidence of nesting in nor around that nook so we moved along the hillside. After covering about fifty more yards I was surprised when a third poorwill flushed from the base of a bush to my left. That bird landed a short distance away and did a distraction display, which clued me in to that fact that it had flushed from a nest site. I immediately realized that the poorwill was doing what nature had programmed it to do--protect its offspring. The bird appeared to be a female because it lacked the white corners that males have in their tail feathers. Since both sexes are known to incubate it can't be taken for granted that a bird flushing from a nest site is a female.

Common Poorwill Distraction Display Near Nest Site Great Basin Desert Utah

Rather than follow the bird after it flushed I inspected the base of the bush from which the bird had flown.  I beamed with excitement when I observed two white eggs and promptly alerted Eric so he could observe the eggs as well.

Common Poorwill Nest Site Great Basin Desert Utah

Common Poorwill Nest Site Great Basin Desert Utah

The previous images illustrate typical nesting behavior for Common Poorwills--laying their eggs in gravelly areas next to bushes that provides a fair amount of shade. These two eggs were on the south side of a bush on a south-facing hillside. They were situated in a way that allowed morning sun followed by shade from mid-morning through evening. Because I am fascinated by nature and the cycle of life, and because it is quite rare to find a poorwill nest site, I shared with Eric my desire to carefully and briefly revisit the site every few days to document the progress.

Several days later on June 13th we returned to the site and observed that an adult was still incubating the eggs.

Common Poorwill Incubating Eggs Great Basin Desert Utah

Common Poorwill Incubating Eggs Great Basin Desert Utah

I returned to the site by myself on June 17th to discover that one chick had just hatched and the second was in the process of hatching.

Common Poorwill Hatchling and Egg Great Basin Desert Utah

The upper right edge of the remaining egg shows evidence of a breach, evidence that the second chick was in the process of hatching. The tiny beak, nostrils, and eyelids were the only distinguishing features among the messy fluff of down feathers.

Common Poorwill Hatchling and Egg Great Basin Desert Utah

Common Poorwill Egg Shell Being Breached By Chick Great Basin Desert Utah

I made another quick visit to the site on June 19th, ten days after initially discovering the two eggs, with hopes of confirming that the second chick had successfully hatched. Sure enough the adult had two chicks tucked under its chest. The down feathers of one chick can be seen slightly protruding from beneath the bird's left side, the right side from our perspective.

Common Poorwill on Chicks at Nest Site Great Basin Desert Utah

Common Poorwill on Chicks at Nest Site Great Basin Desert Utah

The adult moved away and began its distraction display as I slowly approached. I quickly captured images of the chicks for documentation purposes and left the site.

Common Poorwill Hatchlings at Nest Site Great Basin Desert Utah

Common Poorwill Hatchlings at Nest Site Great Basin Desert Utah

When I returned on the 23rd, just under a week after the chicks had hatched, down feathers were being replaced by pin feathers on both chicks.

Common Poorwill Hatchlings at Nest Site Great Basin Desert Utah

On the 27th, about ten days after hatching, both chicks were still at their hatch site and were beginning to show signs of typical cryptic plumage.

Common Poorwill Chicks at Nest Site Great Basin Desert Utah

Common Poorwill Chicks at Nest Site Great Basin Desert Utah

Common Poorwill Chicks at Nest Site Great Basin Desert Utah

As I was leaving the area after this afternoon visit I noticed that my truck was registering a temperature of 101 degrees Fahrenheit. It was a reminder of some of the harsh conditions that are endured by creatures that live in our local desert.

My last observation of the two chicks took place on the 30th, nearly two weeks after the chicks had hatched. Eric joined me on this trip. We discovered that the birds had fledged and moved to a new roosting site about 20 yards up the hill from their hatch site. Knowing that it might be my last observation since the birds had ventured from their hatch site I took the opportunity to capture detailed images of their plumage and features.

Common Poorwill Fledglings Near Original Hatch Site Great Basin Desert Utah

Common Poorwill Fledgling Beak and Nostril Detail

Common Poorwill Fledgling Crown Feather Development

Common Poorwill Fledgling Feather Development

Common Poorwill Fledgling Feather Development

Common Poorwill Fledgling Feather Development

This image was captured to remind me of where the eggs were laid and where I last saw the chicks because I was unable to locate them several days later when I made my last attempt to observe their development. I feel grateful for the opportunity to watch those chicks develop. I'm also grateful to have a desert playground to explore so close to home.